Patterns of Recurrence and Survival after Surgery or Stereotactic Radiotherapy for Early Stage NSCLC

Immunotherapy-Boosted Stereotactic Ablative Radiotherapy in Inoperable Early-Stage Non-Small Cell Lung Cancer

OPINION STATEMENT

The combination of stereotactic ablative radiotherapy (SABR) with immune checkpoint inhibitors, known as iSABR, marks a significant evolution in treating early-stage, inoperable non-small cell lung cancer (NSCLC). Managing these cases requires a multidisciplinary approach involving radiation and medical oncologists. Clinical evidence from a meta-analysis of seven studies, including 462 patients, indicates that iSABR may offer better outcomes than SABR alone. The analysis showed significantly improved progression-free survival (PFS) rates at 1-, 2-, and 3-year follow-ups for iSABR compared to SABR. There was also a trend toward better overall survival (OS) with iSABR. Subgroup analyses highlighted enhanced 3-year PFS with programmed death-1 (PD-1) inhibitors and doses per fraction ≥ 12.5 Gy. While iSABR slightly increased the risk of grade ≥ 3 adverse events like pneumonitis, fatigue, and skin reactions, these risks are generally manageable within a multidisciplinary treatment framework. In conclusion, iSABR demonstrates potential benefits and manageable risks in phase I/II trials for early-stage, inoperable NSCLC, with improved PFS and acceptable toxicity. These findings warrant further investigation in a larger phase III prospective randomized controlled trial to validate efficacy, optimize protocols, and establish long-term safety.

Decoding Recurrence in Early-Stage and Locoregionally Advanced Non-Small Cell Lung Cancer: Insights From Electronic Health Records and Natural Language Processing

PURPOSE

Recurrences after curative resection in early-stage and locoregionally advanced non-small cell lung cancer (NSCLC) are common, necessitating a nuanced understanding of associated risk factors. This study aimed to establish a natural language processing (NLP) system to efficiently curate recurrence data in NSCLC and analyze risk factors longitudinally.

PATIENTS AND METHODS

Electronic health records of 6,351 patients with NSCLC with >700,000 notes were obtained from Mount Sinai's data sets. A deep learning-based customized NLP system was developed to identify cohorts experiencing recurrence. Recurrence types and rates over time were stratified by various clinical features. Cohort description analysis, Kaplan-Meier analysis for overall recurrence-free survival (RFS) and distant metastasis-free survival (DMFS), and Cox proportional hazards analysis were performed.

RESULTS

Of 1,295 patients with stage I-IIIA NSCLC with surgical resections, 336 patients (25.9%) experienced recurrence, as identified through NLP. The NLP system achieved a precision of 94.3%, a recall of 93%, and an F1 score of 93.5. Among 336 patients, 52.4% had local/regional recurrences, 44% distant metastases, and 3.6% unknown recurrence. RFS rates at years 1-5 were 93%, 81%, 73%, 67%, and 61%, respectively (96%, 89%, 84%, 80%, and 75% for distant metastasis). Stage-specific RFS rates at year 5 were 73% (IA), 62% (IB), 47% (IIA), 46% (IIB), and 20% (IIIA). Stage IB patients had a significantly higher likelihood of recurrence versus stage IA (adjusted hazard ratio [aHR], 1.63; P = .02). The RFS was lower in patients with clinically significant TP53 alteration (v TP53-negative or unknown significance), affecting overall RFS (aHR, 1.89; P = .007) and DMFS (aHR, 2.47; P = .009) among stage IA/IB patients.

CONCLUSION

Our scalable NLP system enabled us to generate real-world insights into NSCLC recurrences, paving the way for predictive models for preventing, diagnosing, and treating NSCLC recurrence.

Efficacy of contrast versus non-contrast CT surveillance among patients surviving two years without recurrence after surgery for stage I lung cancer

Contrast-enhanced chest CT (CECT) is more sensitive than non-contrast-enhanced chest CT (NCECT), but NCECT may have comparable efficacy in detecting new primary lung cancer among stage I NSCLC survivors after two years of surveillance. This study aimed to evaluate the efficacy of NCECT versus CECT for surveillance among stage I NSCLC patients surviving two years after curative resection without disease recurrence. We conducted a retrospective cohort study of patients with stage I NSCLC who underwent curative-intent lung resection between January 2009 and December 2017 using the Registry for Thoracic Cancer Surgery at the Samsung Medical Center, Seoul, Korea. Overall survival, recurrence-free survival, and cost effectiveness were compared between patients undergoing surveillance with CECT and NCECT. Among 3248 patients, 1002 (38.8%) patients underwent NCECT surveillance. During a median follow-up of 2.3 years (interquartile range, 1.5-3.9 years), a total of 208 deaths were observed. Although patients undergoing NCECT surveillance had 0.04 more deaths per 100 person-year compared with patients undergoing CECT surveillance (95% CI -0.36 to 0.44), this difference did not reach statistical significance (1.27 vs. 1.31 per 100 person-years; HR, 1.10; 95% CI 0.81-1.50). Regarding cost effectiveness, CECT group had a gain of 0.024 quality-adjusted life-year but $785 higher total cumulative cost per patient compared to NCECT. There was no difference in recurrence and mortality between NCECT and CECT for surveillance among stage I NSCLC patients who survived two years after surgery without disease recurrence. Further randomized clinical trials are required to confirm the findings.

Lung Microbial and Host Genomic Signatures as Predictors of Prognosis in Early-Stage Adenocarcinoma

BACKGROUND

Risk of early-stage lung adenocarcinoma recurrence after surgical resection is significant, and the postrecurrence median survival is approximately 2 years. Currently, there are no commercially available biomarkers that predict recurrence. In this study, we investigated whether microbial and host genomic signatures in the lung can predict recurrence.

METHODS

In 91 patients with early-stage (stage IA/IB) lung adenocarcinoma with extensive follow-up, we used 16s rRNA gene sequencing and host RNA sequencing to map the microbial and host transcriptomic landscape in tumor and adjacent unaffected lung samples.

RESULTS

Of 91 subjects, 23 had tumor recurrence over 5-year period. In tumor samples, lung adenocarcinoma recurrence was associated with enrichment in Dialister and Prevotella, whereas in unaffected lung samples, recurrence was associated with enrichment in Sphingomonas and Alloiococcus. The strengths of the associations between microbial and host genomic signatures with lung adenocarcinoma recurrence were greater in adjacent unaffected lung samples than in the primary tumor. Among microbial-host features in the unaffected lung samples associated with recurrence, enrichment in Stenotrophomonas geniculata and Chryseobacterium was positively correlated with upregulation of IL2, IL3, IL17, EGFR, and HIF1 signaling pathways among the host transcriptome. In tumor samples, enrichment in Veillonellaceae (Dialister), Ruminococcaceae, Haemophilus influenzae, and Neisseria was positively correlated with upregulation of IL1, IL6, IL17, IFN, and tryptophan metabolism pathways.

CONCLUSIONS

Overall, modeling suggested that a combined microbial/transcriptome approach using unaffected lung samples had the best biomarker performance (AUC = 0.83).

IMPACT

This study suggests that lung adenocarcinoma recurrence is associated with distinct pathophysiologic mechanisms of microbial-host interactions in the unaffected lung rather than those present in the resected tumor.

Association between tumor cell in air space and treatment outcomes in early-stage lung cancer treated with stereotactic body radiation therapy

Background and purpose

Spread-through air space (STAS) is an unfavorable factor in patients with lung cancer treated with surgery. However, the relationship between the treatment outcomes of stereotactic body radiation therapy (SBRT) for lung cancer and STAS has not been adequately investigated. This study aimed to evaluate the impact of tumor cells in the air space (TCIAS), which show a STAS burden, on treatment outcomes in patients with early-stage lung cancer treated with SBRT.

Materials and methods

Data of patients who underwent SBRT for early-stage lung cancer treated with SBRT were retrospectively reviewed. The influence of the TCIAS status on local progression-free (LPF), regional failure-free (RFF), distant failure-free (DFF), progression-free survival (PFS), and overall survival (OS) rates was assessed using univariate and multivariate analyses.

Results

Overall, 68 patients were included. The median follow-up time was 24.3 months. For patients positive/negative for TCIAS, the 2-year LPF, RFF, DFF, PFS, and OS rates were 81.4 %/91.1 %, 73.7 %/96.2 %, 55.9 %/75.3 %, 55.0 %/84.6 %, and 67.8 %/92.2 %, respectively. In the multivariate analysis, TCIAS-positive was a significant unfavorable factor for RFF (hazard ratio [HR]: 4.10; 95 % confidence interval [CI]: 1.04-16.16, p = 0.04), DFF (HR: 2.61, 95 % CI: 1.03-6.57, p = 0.04), and PFS (HR: 2.36; 95 % CI: 1.05-5.30, p = 0.04). By contrast, TCIAS-positive was not a significant risk factor for LPF and OS.

Conclusion

TCIAS-positive is an unfavorable factor for regional and distant failure after SBRT. TCIAS status may be useful in predicting the treatment outcome of SBRT for early-stage lung cancer.

Circulating microbiome DNA as biomarkers for early diagnosis and recurrence of lung cancer

Lung cancer mortality is exacerbated by late-stage diagnosis. Emerging evidence indicates the potential clinical significance of distinct microbial signatures as diagnostic and prognostic biomarkers across various cancers. However, circulating microbiome DNA (cmDNA) profiles are underexplored in lung cancer (LC). Here, whole-genome sequencing is performed on plasma of LC patients and healthy controls (HCs). Differentially enriched microbial species are identified between LC and HC. A diagnostic model is developed, which has a high sensitivity of 87.7% and achieves an AUC of 93.2% in the independent validation dataset. Crucially, this model demonstrates the capability to detect early-stage LC, achieving a sensitivity of 86.5% for stage I and 87.1% for tumors <1 cm. In addition, we construct a cmDNA model for recurrence, which precisely predicts LC recurrence after surgery. Overall, this study highlights the significant alterations of cmDNA profiles in LC, indicating its potential as biomarkers for early diagnosis and recurrence.

Intratumor microbiome-derived butyrate promotes lung cancer metastasis

Most recurrences of lung cancer (LC) occur within 3 years after surgery, but the underlying mechanism remains unclear. Here, we collect LC tissues with shorter (<3 years, recurrence group) and longer (>3 years, non-recurrence group) recurrence-free survival. By using 16S sequencing, we find that intratumor microbiome diversity is lower in the recurrence group and butyrate-producing bacteria are enriched in the recurrence group. The intratumor microbiome signature and circulating microbiome DNA can accurately predict LC recurrence. We prove that intratumor injection of butyrate-producing bacteria Roseburia can promote subcutaneous tumor growth. Mechanistically, bacteria-derived butyrate promotes LC metastasis by increasing expression of H19 in tumor cells through inhibiting HDAC2 and increasing H3K27 acetylation at the H19 promoter and inducing M2 macrophage polarization. Depletion of macrophages partially abolishes the metastasis-promoting effect of butyrate. Our results provide evidence for the cross-talk between the intratumor microbiome and LC metastasis and suggest the potential prognostic and therapeutic value of the intratumor microbiome.

Metastases-directed local therapies (MDT) beyond genuine oligometastatic disease (OMD): Indications, endpoints and the role of imaging

To further personalise treatment in metastatic cancer, the indications for metastases-directed local therapy (MDT) and the biology of oligometastatic disease (OMD) should be kept conceptually apart. Both need to be vigorously investigated. Tumour growth dynamics - growth rate combined with metastatic seeding efficiency - is the single most important biological feature determining the likelihood of success of MDT in an individual patient, which might even be beneficial in slowly developing polymetastatic disease. This can be reasonably well assessed using appropriate clinical imaging. In the context of considering appropriate indications for MDT, detecting metastases at the edge of image resolution should therefore suggest postponing MDT. While three to five lesions are typically used to define OMD, it could be argued that countability throughout the course of metastatic disease, rather than a specific maximum number of lesions, could serve as a better parameter for guiding MDT. Here we argue that the unit of MDT as a treatment option in metastatic cancer might best be defined not as a single procedure at a single point in time, but as a series of treatments that can be delivered in a single or multiple sessions to different lesions over time. Newly emerging lesions that remain amenable to MDT without triggering the start of a new systemic treatment, a change in systemic therapy, or initiation of best supportive care, would thus not constitute a failure of MDT. This would have implications for defining endpoints in clinical trials and registries: Rather than with any disease progression, failure of MDT would only be declared when there is progression to polymetastatic disease, which then precludes further options for MDT.

SABR for Early Non-Small Cell Lung Cancer: Changes in Pulmonary Function, Dyspnea, and Quality of Life

PURPOSE

The aim of this study was to report pulmonary function tests (PFTs) and clinician-reported and patient-reported quality-of-life (QoL) outcomes on a cohort of patients with non-small cell lung cancer (NSCLC) treated with SABR.

METHODS AND MATERIALS

A total of 119 patients with NSCLC were treated with SABR in the prospective cohort SSBROC study of patients with T1-T2N0M0 NSCLC. PFTs and QoL measures were obtained at baseline pretreatment and at 6-month intervals. Here we report on the 6- to 18-month time points. Analysis of covariance (ANCOVA) methods adjusting for baseline analyzed potential predictors on outcomes of PFTs and patient-reported dyspnea at 18 months.

RESULTS

The only statistically significant decline in PFTs was seen in forced expiratory volume in 1 second (FEV1) at 18 months post-SABR, with a decline of -0.11 L (P = .0087; 95% CI, -0.18 to -0.02). Of potential predictors of decline, only a 1-unit increase in smoking pack-years resulted in a -0.12 change in diffusing capacity for carbon monoxide (P = .026; 95% CI, -0.02 to -0.23) and a 0.003 decrease in FEV1 (P = .026; 95% CI, -0.006 to -0.0004). For patient-reported outcomes, statistically significant worsening in both the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (QLQ-C30 Version 3) and the lung module (QLQ-LC13) dyspnea scores occurred at the 18-month time point, but not earlier. No potential predictors of worsening dyspnea were statistically significant. There was no statistically significant decline in clinician-reported outcomes or global QoL scores.

CONCLUSIONS

We found a statistically significant decline in FEV1 at 18 months posttreatment. Smoking pack-years was a predictor for decline in diffusing capacity for carbon monoxide and FEV1 at 18 months. Worsening of patient-reported dyspnea scores was observed, consistent with the expected progression of lung comorbid disease.

[Impact of immunotherapy on the therapeutic strategy for the management of stage I non-small cell lung cancer: The radiation oncologist's point of view]

Surgery is the standard treatment for operable patients with stage I non-small cell lung cancer (NSCLC) (T1-T2aN0M0). Stereotactic body radiotherapy (SBRT) is the treatment of choice for non-operable patients, and its positioning for operable patients remains to be clarified. The pattern of recurrence after management of stage I NSCLC is dominated by the risk of distant recurrence, this constituting the rationale for the adjunction of systemic treatment, and especially check point inhibitor (CPI), in combination with surgery or SBRT for patients with high risk features. While the benefit of postoperative CPI on the micro-metastatic disease is logically considered within the framework of a simply additive effect of both therapeutic modalities, it is reasonable to consider a synergistic effect of both CPI and SBRT. Given the role of tumor draining nodes in the development of an anti-tumor immune response, a "tumor-draining node sparing" strategy enabled by SBRT could therefore be of major interest in combination with CPI. Pending confirmation of the role of CPI in combination with RTS for the management of stage I NSCLC, we thus discuss in this review the theoretical advantages that this therapeutic strategy could have compared to a surgical strategy.

Temporal genomic heterogeneity guiding individualized therapy in recurrent non-small cell lung cancer

Introduction

Despite the benefit of adjuvant systemic therapy for patients with resected non-small cell lung cancer (NSCLC), the risk of postoperative recurrence remains high. Our objective was to characterize temporal genetic heterogeneity between primary resected and recurrent tumors, and its impact on treatment outcomes.

Methods

In this study, next-generation sequencing (NGS) testing was performed on tissue specimens and circulating tumor DNA (ctDNA) collected at postoperative recurrence, and results were compared to the genotypes of initial surgical specimens.

Results

Of forty-five patients with matched primary and post-operative recurrent tumors, EGFR status switched in 17 patients (37.8%) at post-operative recurrence and 28 patients (62.2%) had no genotype change (17 mutant, 11 wild-type). Based on the changes of EGFR status, patients were divided into 4 groups. Following subsequent treatment with EGFR TKI o chemotherapy: In group A, with sustained sensitive mutation, the percentage achieving partial response (PR) was the highest, at 72.2%, the median progression-free survival (PFS) was 17 months, and the median overall survival (OS) was 44.0 months respectively; In group B, with genotype changed from wild-type to mutant, 50% achieved PR, PFS was 10 months, and OS was 35 months; In group C, in which mutant status shifted to wild-type or new co-mutation emerged, the percentage achieving PR was 30%, PFS was 9 months, and OS was 35 months. In group D, with sustained wild type, the percentage achieving PR was 27.3%, PFS was 8 months, and OS was 22 months.

Discussion

Genotypic shift between paired primary and post-operative recurrent tumors was not infrequent, and this temporal genomic heterogeneity substantially impacted subsequent treatment outcomes.

Role of circulating-tumor DNA in the early-stage non-small cell lung carcinoma as a predictive biomarker

Lung cancer is one of the most common solid malignancies. Tissue biopsy is the standard method for accurately diagnosing lung and many other malignancies over decades. However, molecular profiling of tumors leads to establishing a new horizon in the field of precision medicine, which has now entered the mainstream in clinical practice. In this context, a minimally invasive complementary method has been proposed as a liquid biopsy (LB) which is a blood-based test that is gaining popularity as it provides the opportunity to test genotypes in a unique, less invasive manner. Circulating tumor cells (CTC) captivating the Circulating-tumor DNA (Ct-DNA) are often present in the blood of lung cancer patients and are the fundamental concept behind LB. There are multiple clinical uses of Ct-DNA, including its role in prognostic and therapeutic purposes. The treatment of lung cancer has drastically evolved over time. Therefore, this review article mainly focuses on the current literature on circulating tumor DNA and its clinical implications and future goals in non-small cell lung cancer.

STK11 Inactivation Predicts Rapid Recurrence in Inoperable Early-Stage Non-Small-Cell Lung Cancer

PURPOSE

Molecular factors predicting relapse in early-stage non-small-cell lung cancer (ES-NSCLC) are poorly understood, especially in inoperable patients receiving radiotherapy (RT). In this study, we compared the genomic profiles of inoperable and operable ES-NSCLC.

MATERIALS AND METHODS

This retrospective study included 53 patients with nonsquamous ES-NSCLC (stage I-II) treated at a single institution (University of Chicago) with surgery (ie, operable; n = 30) or RT (ie, inoperable; n = 23) who underwent tumor genomic profiling. A second cohort of ES-NSCLC treated with RT (Stanford, n = 39) was included to power clinical analyses. Prognostic gene alterations were identified and correlated with clinical variables. The primary clinical end point was the correlation of prognostic genes with the cumulative incidence of relapse, disease-free survival, and overall survival (OS) in a pooled RT cohort from the two institutions (N = 62).

RESULTS

Although the surgery cohort exhibited lower rates of relapse, the RT cohort was highly enriched for somatic STK11 mutations (43% v 6.7%). Receiving supplemental oxygen (odds ratio [OR] = 5.5), 20+ pack-years of tobacco smoking (OR = 6.1), and Black race (OR = 4.3) were associated with increased frequency of STK11 mutations. In the pooled RT cohort (N = 62), STK11 mutation was strongly associated with inferior oncologic outcomes: 2-year incidence of relapse was 62% versus 20% and 2-year OS was 52% versus 85%, remaining independently prognostic on multivariable analyses (relapse: subdistribution hazard ratio = 4.0, P = .0041; disease-free survival: hazard ratio, 6.8, P = .0002; OS: hazard ratio, 6.0, P = .022). STK11 mutations were predominantly associated with distant failure, rather than local.

CONCLUSION

In this cohort of ES-NSCLC, STK11 inactivation was associated with poor oncologic outcomes after RT and demonstrated a novel association with clinical hypoxia, which may underlie its correlation with medical inoperability. Further validation in larger cohorts and investigation of effective adjuvant systemic therapies may be warranted.

Radiotherapy modulates tumor cell fate decisions: a review

Cancer has always been a worldwide problem, and the application of radiotherapy has greatly improved the survival rate of cancer patients. Radiotherapy can modulate multiple cell fate decisions to kill tumor cells and achieve its therapeutic effect. With the development of radiotherapy technology, how to increase the killing effect of tumor cells and reduce the side effects on normal cells has become a new problem. In this review, we summarize the mechanisms by which radiotherapy induces tumor cell apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis, autophagy, senescence, mitotic catastrophe, and cuproptosis. An in-depth understanding of these radiotherapy-related cell fate decisions can greatly improve the efficiency of radiotherapy for cancer.

Thorax radiotherapy using 18F-positron emission tomography/computed tomography-guided precision radiotherapy is a prognostic factor for survival in patients with extracranial oligometastatic non-small cell lung cancer:A two-center propensity score-matched analysis

Background

This retrospective study compared positron emission tomography (PET)/computed tomography (CT) and CT in the treatment of extracranial oligometastatic non-small-cell lung cancer (NSCLC) and explored the impact of thorax radiotherapy (TRT) on patient survival.

Methods

We reviewed the medical records of Chinese patients with stage IV extracranial oligometastatic NSCLC who underwent PET/CT or CT at two centers. Propensity score matching (PSM) was used to control differences in patient characteristics between the maintenance chemotherapy alone and TRT plus maintenance chemotherapy groups.

Results

We analyzed 192 eligible patients. The median survival time was better in patients who received PET/CT than in those who only received CT (n = 192, 16 months vs. 6 months, p<0.001). Subgroup analysis showed the median survival time was significantly longer in the TRT plus maintenance group than in the chemotherapy alone group in patients who underwent PET/CT examinations (n = 94, 25 months vs. 11 months, p<0.001). However, there was no statistical difference in survival between both groups in patients who underwent CT examinations (n = 98, 8 months vs. 5 months, p = 0.180). A multifactorial analysis revealed a more favorable prognosis in patients who underwent PET/CT evaluation (HR: 0.343, 95% CI: 0.250-0.471, p <0.001) and TRT (HR: 0.624, 95% CI: 0.464-0.840, p = 0.002), than in those who did not. PSM was consistent with these results.

Conclusions

PET/CT-guided TRT is associated with improved clinical outcomes in patients with stage IV extracranial oligometastatic NSCLC.

LIBRETTO-432, a phase III study of adjuvant selpercatinib or placebo in stage IB-IIIA RET fusion-positive non-small-cell lung cancer

Selpercatinib, a first-in-class, highly selective and potent central nervous system-active RET kinase inhibitor demonstrated clinically meaningful activity with manageable toxicity in pretreated and treatment-naive advanced/metastatic RET fusion-positive non-small-cell lung cancer (NSCLC). LIBRETTO-432 is a global, randomized, double-blind, phase III trial evaluating selpercatinib versus placebo in stage IB-IIIA, RET fusion-positive NSCLC, previously treated with definitive surgery or radiation; participants must have undergone available anti-cancer therapy (including chemotherapy or durvalumab) or not be suitable for it, per investigator's discretion. The primary end point is investigator-assessed event-free survival (EFS) in the primary analysis population (stage II-IIIA RET fusion-positive NSCLC). Key secondary end points include EFS in the overall population, overall survival, and time to distant disease recurrence in the central nervous system.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 4: systematic review of evidence involving SBRT and ablation

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options [lobectomy, segmentectomy, wedge, stereotactic body radiotherapy (SBRT), thermal ablation], weighing multiple outcomes (e.g., short-, intermediate-, long-term) and multiple aspects of each (e.g., magnitude of a difference, the degree of confidence in the evidence, and the applicability to the patient and setting at hand). A structure is needed to summarize the relevant evidence for an individual patient and to identify which outcomes have the greatest impact on the decision-making.

Methods

A PubMed systematic review from 2000-2021 of outcomes after SBRT or thermal ablation vs. resection is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons with at least some adjustment for confounders. The analysis involved careful assessment, including characteristics of patients, settings, residual confounding etc. to expose degrees of uncertainty and applicability to individual patients. Evidence is summarized that provides an at-a-glance overall impression as well as the ability to delve into layers of details of the patients, settings and treatments involved.

Results

Short-term outcomes are meaningfully better after SBRT than resection. SBRT doesn't affect quality-of-life (QOL), on average pulmonary function is not altered, but a minority of patients may experience gradual late toxicity. Adjusted non-randomized comparisons demonstrate a clinically relevant detriment in long-term outcomes after SBRT vs. surgery. The short-term benefits of SBRT over surgery are accentuated with increasing age and compromised patients, but the long-term detriment remains. Ablation is associated with a higher rate of complications than SBRT, but there is little intermediate-term impact on quality-of-life or pulmonary function tests. Adjusted comparisons show a meaningful detriment in long-term outcomes after ablation vs. surgery; there is less difference between ablation and SBRT.

Conclusions

A systematic, comprehensive summary of evidence regarding Stereotactic Body Radiotherapy or thermal ablation vs. resection with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation for a framework for individualized decision-making.

Stereotactic body radiotherapy versus surgery for early-stage non-small cell lung cancer: an updated meta-analysis involving 29,511 patients included in comparative studies

Objective:

To evaluate the efficacy of stereotactic body radiotherapy (SBRT) versus surgery for early-stage non-small cell lung cancer (NSCLC) by means of a meta-analysis of comparative studies.

Methods:

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology guidelines, searches were performed on PubMed, MEDLINE, Embase, and Cochrane Library for eligible studies. The meta-analysis compared the hazard ratios (HR) for overall survival (OS), cancer-specific survival (CSS), and local control (LC). Subgroup and meta-regression analyses evaluated the association of extent of surgical resection, study publication year, tumor staging, propensity score matching, proportion of chemotherapy use, and proportion of pathological lymph node involvement with CSS and OS.

Results:

Thirty studies involving 29,511 patients were included (surgery group: 17,146 patients and SBRT group: 12,365 patients). There was a significant difference in favor of surgery vs. SBRT in the 3-year OS (HR = 1.35; 95% CI: 1.22-1.44; I² = 66%) and 3-year CSS (HR = 1.23; 95% CI: 1.09-1.37; I² = 17%), but not in the 3-year LC (HR = 0.97; 95% CI: 0.93-1.08; I² = 19%). In the subgroup analysis for OS, no significant difference between surgery and SBRT groups was observed in the T1N0M0 subgroup (HR = 1.26; 95% CI: 0.95-1.68; I² = 0%). In subgroup analysis for CSS, no significant difference was detected between the sublobar resection subgroup and the SBRT group (HR = 1.21; 95% CI: 0.96-1.53; I² = 16%).

Conclusions:

Surgery generally resulted in better 3-year OS and CSS than did SBRT; however, publication bias and heterogeneity may have influenced these findings. In contrast, SBRT produced LC results similar to those of surgery regardless of the extent of surgical resection. These findings may have important clinical implications for patients with comorbidities, advanced age, poor pulmonary reserve, and other factors that may contraindicate surgery.

Impact of Pre-Treatment NLR and Other Hematologic Biomarkers on the Outcomes of Early-Stage Non-Small-Cell Lung Cancer Treated with Stereotactic Body Radiation Therapy

Introduction: We evaluated the association of pre-treatment immunologic biomarkers on the outcomes of early-stage non-small-cell lung cancer (NSCLC) patients treated with stereotactic body radiation therapy (SBRT). Materials and methods: In this retrospective study, all newly diagnosed early-stage NSCLC treated with SBRT between January 2010 and December 2017 were screened and included for further analysis. The pre-treatment neutrophil-lymphocyte ratio (NLR), monocyte lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) were calculated. Overall survival (OS) and recurrence-free survival (RFS) were estimated by Kaplan–Meier. Multivariable models were constructed to determine the impact of different biomarkers and the Akaike information criterion (AIC), index of adequacy, and scaled Brier scores were calculated. Results: A total of 72 patients were identified and 61 were included in final analysis. The median neutrophil count at baseline was 5.4 × 10⁹/L (IQR: 4.17–7.05 × 10⁹/L). Median lymphocyte count was 1.63 × 10⁹/L (IQR: 1.29–2.10 × 10⁹/L), median monocyte count was 0.65 × 10⁹/L (IQR: 0.54–0.83 × 10⁹/L), median platelet count was 260.0 × 10⁹/L (IQR: 211.0–302.0 × 10⁹/L). The median NLR was 3.42 (IQR: 2.38–5.04), median MLR was 0.39 (IQR: 0.31–0.53), and median PLR was 156.4 (IQR: 117.2–197.5). On multivariable regression a higher NLR was associated with worse OS (p = 0.01; HR-1.26; 95% CI 1.04–1.53). The delta AIC between the two multivariable models was 3.4, suggesting a moderate impact of NLR on OS. On multivariable analysis, higher NLR was associated with poor RFS (p = 0.001; NLR^1 HR 0.36; 0.17–0.78; NLR^2 HR-1.16; 95% CI 1.06–1.26) with a nonlinear relationship. The delta AIC between the two multivariable models was 16.2, suggesting a strong impact of NLR on RFS. In our cohort, MLR and PLR were not associated with RFS or OS in multivariable models. Conclusions: Our study suggests NLR, as a biomarker of systemic inflammation, is an independent prognostic factor for OS and RFS. The nonlinear relationship with RFS may indicate a suitable immunological environment is needed for optimal SBRT action and tumoricidal mechanisms. These findings require further validation in independent cohorts.

Impact of local recurrence on cause-specific death after stereotactic body radiotherapy for early-stage non-small cell lung cancer: dynamic prediction using landmark model

PURPOSE

The purpose of this study was to assess the impact of local recurrence (LR) on cause-specific death (CSD) in patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). A dynamic prediction model that incorporated LR as a time-dependent covariate was used.

METHODS AND MATERIALS

This study included 535 stage I (cT1-T2aN0M0) NSCLC patients treated with SBRT from two institutions. We developed a landmark dynamic prediction model to estimate the probability of a CSD. This model determined the probability of surviving for an additional 3 years at different prediction time points during follow-up, given the history of recurrence status. The baseline covariates included in the model were age, sex, T stage, and histology, while the time-dependent covariates were LR and regional and/or distant recurrence (RDR) status.

RESULTS

Overall, 137 patients (25.6%) died of lung cancer within a median follow-up of 4.1 years. Of the 195 patients who developed recurrence, 28, 125, and 42 patients had LR only, RDR only, and both, respectively. The landmark model showed that older age, advanced T stage, LR, and RDR were significantly associated with an increased risk of subsequent CSD. Among these covariates, LR (odds ratio [OR], 8.5; 95% confidence interval [CI], 6.0-12.0; P < .001) and RDR (OR, 11.6; 95% CI, 9.1-14.9; P < .001) demonstrated strong effects on CSD within 3 years after the prediction time points. The dynamic prediction provided information on the probability of future CSD according to individual recurrence status during follow-up.

CONCLUSIONS

Dynamic prediction using the landmark model showed that LR had a substantial impact on subsequent CSD, which was comparable to that of RDR. This result supports the notion that strategies to improve local control are reasonable.

A Radiomics Nomogram for Preoperative Prediction of Clinical Occult Lymph Node Metastasis in cT1-2N0M0 Solid Lung Adenocarcinoma

Background

Clinical occult lymph node metastasis (cOLNM) means that the lymph node is negatively diagnosed by preoperative computed tomography (CT), but has been proven to be positive by postoperative pathology. The aim of this study was to establish and validate a nomogram based on radiomics features for the preoperative prediction of cOLNM in early-stage solid lung adenocarcinoma patients.

Methods

A total of 244 patients with clinical T1-2N0M0 solid lung adenocarcinoma who underwent preoperative contrast-enhanced chest CT were divided into a primary group (n = 160) and an independent validation group from another hospital (n = 84). The records of 851 radiomics features of each primary tumor were extracted. LASSO analysis was used to reduce the data dimensionality and select features. Multivariable logistic regression was utilized to identify independent predictors of cOLNM and develop a predictive nomogram. The performance of the predictive model was assessed by its calibration and discrimination. Decision curve analysis (DCA) was performed to estimate the clinical usefulness of the nomogram.

Results

The predictive model consisted of a clinical factor (CT-reported tumor size) and a radiomics feature (Rad-score). The nomogram presented good discrimination, with a C-index of 0.782 (95% CI, 0.768–0.796) in the primary cohort and 0.813 (95% CI, 0.787–0.839) in the validation cohort, and good calibration. DCA showed that the radiomics nomogram was clinically useful.

Conclusion

This study develops and validates a nomogram that incorporates clinical and radiomics factors. It can be tailored for the individualized preoperative prediction of cOLNM in early-stage solid lung adenocarcinoma patients.

Immunotherapy for non-small cell lung cancer (NSCLC), as a stand-alone and in combination therapy

Non-small cell lung cancer (NSCLC) is of major concern for society as it is associated with high mortality and is one of the most commonly occurring of all cancers. Due to the number of mutational variants and general heterogeneity of this type of cancer, treatment using conventional modalities has been challenging. Therefore, it is important to have improved therapeutic treatments like immunotherapy, that can specifically treat the disease while causing minimal damage to healthy tissue and additionally provide systemic immunity. Cancer vaccines are an important element of cancer immunotherapy and have been approved for treatment of a limited number of cancers, including NSCLC. This article highlights scientific evidence for several therapeutic treatment strategies for NSCLC, alone or in combination, which offers new hope for those suffering. Although cancer vaccines have had some success as a monotherapy, their potential in a combination therapy needs to be critically analyzed for future applications.

Association of postoperative recurrence with radiological and clinicopathological features in patients with stage IA-IIA lung adenocarcinoma

OBJECTIVES

To retrospectively investigate whether radiological and clinicopathological characteristics were associated with the presence of stage IA-IIA lung adenocarcinoma in patients at high risk for a postoperative recurrence.

MATERIALS AND METHODS

Three hundred twelve patients with biopsy-proven node-negative early-stage (IA-IIA) lung adenocarcinoma met the inclusion criteria for this study. Demographics data and histopathological findings were collected from medical records. Computed tomography (CT) performed approximately 1 month before surgery was manually scored using 23 CT descriptors. Univariate analyses were applied to demonstrate an association between clinicopathological and radiological features and 2-/5-year recurrences. Multivariate logistic regression was performed to assess the ability of radiological and clinicopathological features to discriminate low and high-risk factors for recurrence. A ROC curve was used to evaluate prediction performance.

RESULTS

Univariate analysis revealed that the 2-year recurrence was associated with six radiological features and two clinicopathological features, while 5-year recurrence was associated with five radiological features and two clinicopathological features. A multivariate logistic regression model of combined clinicopathological and radiological features showed that stage IIA (OR = 2.87), solid texture (solid part > 50 %: OR = 4.81; solid part = 100 %: OR = 3.61), pleural attachment (OR = 3.97) and bronchovascular bundle thickening (OR = 2.16) were associated with the independent predictors of 2-year recurrence, and stage IIA (OR = 3.52), solid texture (solid part > 50 %: OR = 3.56; solid part = 100 %: OR = 2.44) and pleural attachment (OR = 4.57) were associated with 5-year recurrence. Combined radiological and clinicopathological features could be significant indicators of 2- and 5-year recurrences (AUC = 0.784 and AUC = 0.815, respectively).

CONCLUSIONS

The combination of radiological and clinicopathological features has the potential to help predict postoperative recurrence in patients with stage IA-IIA lung adenocarcinomas and guide oncologists and patients whether to undergo additional treatment after surgery.

Personal and Prognostic: Tissue and Liquid Biomarkers of Radiotherapeutic Response in Non-Small Cell Lung Cancer

Recent treatment advances have improved outcomes for patients with non-small cell lung cancer (NSCLC), often utilizing tumor molecular characterization to identify targetable mutations. This is further enhanced by advancements in "liquid biopsies", using peripheral blood for noninvasive, serial sampling of tumor biology. While tumor genomic alterations have established therapeutic implications in metastatic NSCLC, research is also ongoing to develop applications for tissue and liquid biomarkers in earlier stage disease, such as patients treated with radiation for early stage or locoregional NSCLC.

Automated gross tumor volume contour generation for large-scale analysis of early-stage lung cancer patients planned with 4D-CT

PURPOSE

Patients with early-stage lung cancer undergoing stereotactic ablative radiotherapy receive four-dimensional computed tomography (4D-CT) for treatment planning. Often, an internal gross target volume (iGTV), which approximates the motion envelope of a tumor over the breathing cycle, is delineated without defining a gross tumor volume (GTV). However, the GTV volume and shape are important parameters for prognostic and dose modelling, and there is interest in radiomic features extracted from the GTV and surrounding tissue. We demonstrate and validate a method to generate the GTV from an iGTV contour to aid retrospective analysis on routine data.

METHOD

It is possible to reconstruct the geometry of a tumor with knowledge of tumor motion and the motion envelope formed during respiration. To demonstrate this, the tumor motion path was estimated with local rigid registration, and the iGTV positioned incrementally at stations along the reverse path. It is shown that the tumor volume is the largest set common to the intersection of the iGTV at these positions, hence can be derived. This was implemented for 521 lung lesions on 4D-CT. Eleven patients with a GTV delineation performed by a radiation oncologist on a reference phase (50%) were used for validation. The generated GTV was compared to that delineated by the expert using distance-to-agreement (DTA), volume, and distance between centres of mass. An overall success rate was determined by detecting registration inaccuracy and performing a quality check on the routine iGTV. For successfully generated contours, GTV volume was compared to iGTV volume in a prognostic model for overall survival.

RESULTS

For the validation dataset, DTA mean (0.79 - 1.55 mm) and standard deviation (0.68 - 1.51 mm) were comparable to expected observer variation. Difference in volume was < 5 cm³ , and average difference in position was 1.21 mm. Deviations in shape and position were mainly caused by observer differences in iGTV and GTV interpretation as opposed to algorithm performance. For the complete dataset, an acceptable contour was generated for 94% of patients using statistical and visual assessment to detect failures. Generated GTV volumes improved prognostic model performance over iGTV volumes.

CONCLUSION

A method to generate a GTV from an iGTV and 4D-CT dataset was developed. This method facilitates data analysis of patients with early-stage lung cancer treated in the routine setting, that is, data mining, prognostic modeling, and radiomics. Generation failure detection removes the need for visual assessment of all contours, reducing a time-consuming aspect of big-data analysis. Favorable prognostic performance of generated GTV volumes over iGTV ones demonstrates opportunities to use this methodology for future study.

Radiotherapy for non-small cell lung cancer in the immunotherapy era: the opportunity and challenge-a narrative review

Immunotherapy has radically changed the clinical management of patients with cancer in recent years. Immune checkpoint inhibitors (ICIs) reversing the immunosuppressive effects of the tumor microenvironment are one type of immunotherapy, several of which are approved by the US Food and Drug Administration (FDA) as first-line treatments for patients with non-small cell lung cancer (NSCLC). However, response rates to ICIs are around 19-47% among patients with advanced NSCLC. As a result, the development of combined ICI and radiotherapy has begun with the aim of strengthening patients' antitumor immunity. Radiotherapy with substantial technological improvements not only achieves local tumor control through the induction of deoxyribonucleic acid (DNA) damage in irradiated regions, but also has the potential to mediate immunostimulatory effects that could result in tumor regression beyond irradiated regions. At present, numerous preclinical and clinical research are investigating the efficiency and safety of combining ICI with radiotherapy. The PACIFIC trial showed that combining chemoradiotherapy with ICI could improve clinical outcomes. In this review, we summarize the rationale for combining radiotherapy with immunotherapy. We also discuss the opportunities and challenges of combination therapy, including the timing of radiotherapy, optimal dose and fractionations, radiotherapy target and target volume, acquired resistance, patient selection, and radioimmunotherapy toxicity.

What is the role of reirradiation in the management of locoregionally relapsed non small-cell lung cancer?

The prognosis of lung cancer patients has improved in the last few years. Despite definitive therapy, local recurrence or a second primary tumour can occur in many patients within previously irradiated areas. Recent developement of more accurate techniques in radiation oncology allows delivery of high radiation dose to the tumor with the aim of improving local control, delaying disease progression and in some cases even curing. Nevertheless, the use of high dose in the reirradiation setting is not without risks, especially when treatment volumes overlap with previously irradiated tissues. The risk of adverse effects must be balanced with the choice of an effective treatment by selecting suitable candidates and the best radiation technique. In this systemic review efficacy and toxicity of reirradiation in locoregionally recurrent non-small-cell lung cancer is extensively discussed. Results indicate that reirradiation might be beneficial in well-selected patients. Prospective and high quality studies are necessary in this field.

Novel treatment strategies for early-stage lung cancer: the oncologist's perspective

Management of early-stage non-small cell lung cancer (NSCLC) consists in multimodal treatment, including surgery, radiotherapy and chemotherapy. The mainstay of treatment is radical surgery. Definitive radiotherapy using stereotactic techniques can provide adequate local disease control, and is the treatment of choice in medically inoperable patients. Most early-stage patients are at significant risk of disease relapse after local treatment. Adjuvant platinum-based chemotherapy has demonstrated to provide an absolute survival benefit of 5% compared to observation. However, unlike advanced/metastatic disease, little progress has been made in the treatment of early-stage NSCLC over the past decade. In recent years, plenty of research has focused on the optimization of adjuvant and neoadjuvant treatment. Several trials with novel drugs, such as targeted agents and immune-checkpoint inhibitors are currently underway, with preliminary positive results. Customization of treatment on patients’ characteristics before, and major pathological response after therapy, will further improve survival outcomes in this subset of patients.

The role of EGFR mutations in predicting recurrence in early and locally advanced lung adenocarcinoma following definitive therapy

Introduction: Roughly one third of new non-small cell lung cancer (NSCLC) is diagnosed at early stages. While lobectomy can improve mortality in this group, about 30–55% of patients will experience disease recurrence. Increased investigation into the factors affecting recurrence, particularly tumor molecular genetics such as EGFR mutations, is needed.

Materials and Methods: We conducted a single-center retrospective study of 282 patients with early or locally advanced lung adenocarcinoma, with or without EGFR mutations, who underwent definitive therapy. We then assessed recurrence, stage at recurrence, time to recurrence and progression-free survival (PFS).

Results: We identified 142 patients with EGFR-mutated and 140 EGFR-wildtype lung adenocarcinoma. Overall progression between groups was equivalent at ~40% at 5 years; no difference in PFS was observed at any time-point. However, among those who recurred, EGFR-mutated lung cancer had increased rates of metastatic recurrence compared to EGFR-wildtype disease (97% vs 68%, p = 0.007).

Conclusions: EGFR-mutated disease may be associated with a higher risk of metastatic recurrence. Molecular testing may be a promising tool for risk stratification and surveillance following definitive management for early stage disease. Future prospective, multi-center cohort studies are needed to confirm these findings and improve our understanding of how EGFR mutation contributes to prognosis and clinical outcomes.

Oncologic Outcomes of Surgery Versus SBRT for Non-Small-Cell Lung Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The optimal treatment of stage I non-small-cell lung carcinoma is subject to debate. The aim of this study was to compare overall survival and oncologic outcomes of lobar resection (LR), sublobar resection (SR), and stereotactic body radiotherapy (SBRT).

METHODS

A systematic review and meta-analysis of oncologic outcomes of propensity matched comparative and noncomparative cohort studies was performed. Outcomes of interest were overall survival and disease-free survival. The inverse variance method and the random-effects method for meta-analysis were utilized to assess the pooled estimates.

RESULTS

A total of 100 studies with patients treated for clinical stage I non-small-cell lung carcinoma were included. Long-term overall and disease-free survival after LR was superior over SBRT in all comparisons, and for most comparisons, SR was superior to SBRT. Noncomparative studies showed superior long-term overall and disease-free survival for both LR and SR over SBRT. Although the papers were heterogeneous and of low quality, results remained essentially the same throughout a large number of stratifications and sensitivity analyses.

CONCLUSION

Results of this systematic review and meta-analysis showed that LR has superior outcomes compared to SBRT for cI non-small-cell lung carcinoma. New trials are underway evaluating long-term results of SBRT in potentially operable patients.

Lung cancer staging: State of the art in the era of ablative therapies and surgical segmentectomy

Implementation of lung cancer screening and improvements in imaging are expected to increase the proportion of lung cancer diagnosed at an early stage. The standard of care has historically been anatomic lobectomy; however, there is now an array of surgical and non-surgical approaches for management of local disease either in active use or under investigation. By their nature, these new modalities offer a theoretical trade-off of reduced morbidity in exchange for reduced efficacy in the setting of advanced disease. It is therefore critical that patients being considered for these approaches (e.g. surgical segmentectomy and SABR) be accurately staged to maximize the potential for definitive treatment. In this article, we will review current approaches to the staging of patients being considered for segmentectomy or ablation. This will serve as a foundation to highlight important questions deserving further investigation.

Effects of the recurrence pattern on patient survival following SABR for stage I lung cancer

Background: Information on the effect of the recurrence pattern on survival for stage I lung cancer following stereotactic ablative radiotherapy (SABR) is limited.Materials and Methods: The recurrence pattern was analyzed for 100 consecutive stage I non-small-cell lung cancer patients treated with SABR using predominantly 12 Gy × 4. Recurrences were classified as local, regional lymph nodes and distant. Distant recurrences included recurrences in the lung and outside the chest. Single lung recurrences were named solitary, if no other location was involved. Kaplan-Meier survival estimates were calculated for different locations of recurrence. Clinical and dosimetrical factors affecting survival were also analyzed.Results: Median follow-up was 32 months (3-123), median age 70 years (49-95). In total, 31 patients had recurrences after a median 21 months (4-60): 5 local; 10 regional; 8 distant outside the chest; 25 non-local lung recurrences, of which 15 were single - 10 of which solitary - and 10 multiple lung nodules. Patients with a solitary lung recurrence had longer survival compared to local or distant recurrences (p = .04 each), and compared to multiple lung nodules (p = .09). 3-year local recurrence-free survival was 92%, disease-free survival 69% and overall survival 59%. On multivariate analysis, disease-free survival was associated with statin use (p = .038) and tumor location (p = .035). Smoking history predicted overall survival (p < .0006).Conclusions: A total of 81% of recurrences involved the lungs. Patients with solitary lung recurrences/second primary lung cancers had the longest overall survival suggesting definitive treatment should be considered. The effects of statin use need to be explored further.

A Model-Based Cost-Effectiveness Analysis of an Exercise Program for Lung Cancer Survivors After Curative-Intent Treatment

OBJECTIVE

The cost-effectiveness of exercise interventions in lung cancer survivors is unknown. We performed a model-based cost-effectiveness analysis of an exercise intervention in lung cancer survivors.

DESIGN

We used Markov modeling to simulate the impact of the Lifestyle Interventions and Independence for Elders exercise intervention compared with usual care for stage I-IIIA lung cancer survivors after curative-intent treatment. We calculated and considered incremental cost-effectiveness ratios of less than US $100,000/quality-adjusted life-year as cost-effective and assessed model uncertainty using sensitivity analyses.

RESULTS

The base-case model showed that the Lifestyle Interventions and Independence for Elders exercise program would increase overall cost by US $4740 and effectiveness by 0.06 quality-adjusted life-years compared with usual care and have an incremental cost-effectiveness ratio of US $79,504/quality-adjusted life-year. The model was most sensitive to the cost of the exercise program, probability of increasing exercise, and utility benefit related to exercise. At a willingness-to-pay threshold of US $100,000/quality-adjusted life-year, Lifestyle Interventions and Independence for Elders had a 71% probability of being cost-effective compared with 27% for usual care. When we included opportunity costs, Lifestyle Interventions and Independence for Elders had an incremental cost-effectiveness ratio of US $179,774/quality-adjusted life-year, exceeding the cost-effectiveness threshold.

CONCLUSIONS

A simulation of the Lifestyle Interventions and Independence for Elders exercise intervention in lung cancer survivors demonstrates cost-effectiveness from an organization but not societal perspective. A similar exercise program for lung cancer survivors may be cost-effective.

Is the Combination of Immunotherapy and Radiotherapy in Non-small Cell Lung Cancer a Feasible and Effective Approach?

For many years, conventional oncologic treatments such as surgery, chemotherapy, and radiotherapy (RT) have dominated the field of non-small-cell lung cancer (NSCLC). The recent introduction of immunotherapy (IT) in clinical practice, especially strategies targeting negative regulators of the immune system, so-called immune checkpoint inhibitors, has led to a paradigm shift in lung cancer as in many other solid tumors. Although antibodies against programmed death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) are currently on the forefront of the immuno-oncology field, the first efforts to eradicate cancer by exploiting the host's immune system date back to several decades ago. Even then, researchers aimed to explore the addition of RT to IT strategies in NSCLC patients, attributing its potential benefit to local control of target lesions through direct and indirect DNA damage in cancer cells. However, recent pre-clinical and clinical data have shown RT may also modify antitumor immune responses through induction of immunogenic cell death and reprogramming of the tumor microenvironment. This has led many to reexamine RT as a partner therapy to immuno-oncology treatments and investigate their potential synergy in an exponentially growing number of clinical trials. Herein, the authors review the rationale of combining IT and RT across all NSCLC disease stages and summarize both historical and current clinical evidence surrounding these combination strategies. Furthermore, an overview is provided of active clinical trials exploring the IT-RT concept in different settings of NSCLC.

Predicting 5-Year Progression and Survival Outcomes for Early Stage Non-small Cell Lung Cancer Treated with Stereotactic Ablative Radiation Therapy: Development and Validation of Robust Prognostic Nomograms

PURPOSE

Our purpose was to develop predictive nomograms for overall survival (OS), progression-free survival (PFS), and time-to-progression (TTP) at 5 years in patients with early-stage non-small cell lung cancer (ES-NSCLC) treated with stereotactic ablative radiation therapy (SABR).

METHODS AND MATERIALS

The study cohort included 714 ES-NSCLC patients treated with SABR from 2004-2015 with median follow-up of 59 months, divided into training and testing sets (8:2), with the former used for nomogram development. The least absolute shrinkage and selection operator were initially employed to screen for predictors of OS, PFS, and TTP, and identified predictors were subsequently applied toward Cox proportional hazards regression modeling. Significant predictors (P < .05) on multivariable regression were then used to develop nomograms, which were validated via evaluation of concordance indexes (C-index) and calibration plots. Finally, Kaplan-Meier method and Gray's test were employed to compare and confirm differences in outcomes among various groups and explore prognostic factors associated with local versus distant disease progression.

RESULTS

Significant predictors of both OS and PFS at 5 years included age, sex, Charlson comorbidity index, diffusing capacity of carbon monoxide, systemic immune-inflammation index, and tumor size (P ≤ .01 for all). Eastern Cooperative Oncology Group performance status predicted for OS as well (P = .01), and both tumor size (P < .01) and minimum biological equivalent dose to 95% of planning target volume (PTV D95 BED₁₀; P < .01) were predictive of TTP. The C-indexes for the OS, PFS, and TTP nomograms were 0.73, 0.68, and 0.60 in the training data set and 0.72, 0.66, and 0.59 in the testing data set, respectively. Tumor size > 2.45 cm and PTV D95 BED₁₀ < 113 Gy were significantly associated with both local and distant progression.

CONCLUSIONS

These prognostic nomograms can accurately predict for OS, PFS, and TTP at 5 years after SABR for ES-NSCLC and may thus help identify high-risk patients who could benefit from additional systemic therapy.

Surgery and stereotactic body radiotherapy for early stage non-small cell lung cancer: review of meta-analyses

Observational or randomized studies on survival outcome following surgery versus stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) demonstrated various results, and several meta-analyses on this topic have been published. The PubMed database was queried for meta-analyses comparing surgery and SBRT for early stage NSCLC. Six meta-analyses on this comparison were identified and 4 (66.7%) suggested that surgery be associated with significantly more favorable overall survival than SBRT, using odds ratio or hazard ratio (HR) as measures of effect. Most of the included studies in the meta-analyses were observational studies and those meta-analyses should be interpreted with caution.

Stereotactic Body Radiotherapy Versus Surgery for Early-Stage Non-Small-Cell Lung Cancer

BACKGROUND

Surgery is the gold standard therapy for patients with early-stage non-small-cell lung cancer (NSCLC). However, stereotactic body radiotherapy (SBRT) may provide as an alternative for patients who are medically inoperable or refuse surgical resection. The optimal treatment (SBRT or surgery) for patients with early-stage NSCLC is not clear.

METHODS

A systematic search was performed from PubMed, MEDLINE, Embase, and the Cochrane Library. Study heterogeneity and publication bias were estimated.

RESULTS

Fourteen cohort studies involving 1438 participants (719 who received SBRT and 719 who received surgery) were included in the meta-analysis. The main bias sources between the two groups, such as age, gender, tumor diameter, forced expiratory volume in 1 s, and Charlson comorbidity index were matched. The surgery was associated with a better overall survival (OS) and long-term distant control (DC) for early-stage NSCLC. The pooled OR and 95% confidence interval (CI) for 1-y, 3-y, 5-y OS, and 5-y DC were 1.56 (1.12-2.15), 1.86 (1.50-2.31), 2.43 (1.80-3.28), and 2.74 (1.12-6.67), respectively. No difference was found between the treatments in the 1-y and 3-y disease-free survival; 1-y, 3-y and 5-y locoregional control; or 1-y and 3-y DC.

CONCLUSIONS

Our results found a superior OS and long-term DC for early-stage NSCLC after surgery compared with SBRT after propensity score matching.

The Accuracy of Clinical Staging of Stage I-IIIa Non-Small Cell Lung Cancer: An Analysis Based on Individual Participant Data

BACKGROUND

Clinical staging of non-small cell lung cancer (NSCLC) helps determine the prognosis and treatment of patients; few data exist on the accuracy of clinical staging and the impact on treatment and survival of patients. We assessed whether participant or trial characteristics were associated with clinical staging accuracy as well as impact on survival.

METHODS

We used individual participant data from randomized controlled trials (RCTs), supplied for a meta-analysis of preoperative chemotherapy (± radiotherapy) vs surgery alone (± radiotherapy) in NSCLC. We assessed agreement between clinical TNM (cTNM) stage at randomization and pathologic TNM (pTNM) stage, for participants in the control group.

RESULTS

Results are based on 698 patients who received surgery alone (± radiotherapy) with data for cTNM and pTNM stage. Forty-six percent of cases were cTNM stage I, 23% were cTNM stage II, and 31% were cTNM stage IIIa. cTNM stage disagreed with pTNM stage in 48% of cases, with 34% clinically understaged and 14% clinically overstaged. Agreement was not associated with age (P = .12), sex (P = .62), histology (P = .82), staging method (P = .32), or year of randomization (P = .98). Poorer survival in understaged patients was explained by the underlying pTNM stage. Clinical staging failed to detect T4 disease in 10% of cases and misclassified nodal disease in 38%.

CONCLUSIONS

This study demonstrates suboptimal agreement between clinical and pathologic staging. Discrepancies between clinical and pathologic T and N staging could have led to different treatment decisions in 10% and 38% of cases, respectively. There is therefore a need for further research into improving staging accuracy for patients with stage I-IIIa NSCLC.

Radiotherapy-Induced Senescence and its Effects on Responses to Treatment

Radiotherapy is still a treatment of choice for many malignancies, often in combination with other strategies. However, its efficacy is limited by the dose that can be safely administered without eliciting serious side-effects, as well as the fact that recurrence is common, particularly in large tumours. Combining radiotherapy with drugs that could sensitise cells to radiation and/or reduce the factors that promote the recovery of the surviving cancer cells is a promising approach. Ionising radiation has been shown to induce senescence and the accumulation of senescent cells creates a microenvironment that facilitates neoplastic growth. This provides a rationale to test the addition of anti-senescent drugs, some of which are already available in the clinic, to radiotherapy protocols. Here, we discuss the relevance of radiotherapy-induced senescent cell accumulation and the potential interventions to minimise its negative effects.

Contact of a tumour with the pleura is not associated with regional recurrence following stereotactic ablative radiotherapy for early stage non-small cell lung cancer

BACKGROUND AND PURPOSE

The aim was to investigate the incidence of isolated regional failure following stereotactic ablative radiotherapy (SABR) and risk factors for recurrence.

MATERIALS AND METHODS

Early stage non-small cell lung cancer (NSCLC) patients treated with SABR were included in this retrospective cohort study, with isolated regional recurrence (IRR) as primary endpoint, distant recurrence (DR) and overall survival (OS) as secondary endpoints. Survival analyses were performed using the cumulative incidence function (IRR and DR) or the Kaplan-Meier method (OS) and Cox proportional hazards modelling for univariate and multivariate analyses. The prognostic effect of contact between the tumour and the pleura was investigated using the CT scans used for SABR planning.

RESULTS

A total of 554 patients were included, of whom 494 could be analysed for IRR. The median follow-up for surviving patients was 48.1 months. Twenty-one patients developed an IRR (4%). The cumulative incidence of IRR and DR after 1-, 2-, and 5 years was 2%, 3%, 7% and 8%, 15% and 21%, respectively. Two year OS was 71%. The presence and type of pleural contact was not associated with any of the studied outcomes.

CONCLUSION

The presence, type and length of pleural contact as surrogate for visceral pleural invasion were not predictive for outcome. Further studies focussing on risk factors for occult nodal involvement, (I)RR, distant metastases and mortality in early stage NSCLC are warranted for the development of risk adapted diagnostic, treatment and follow-up strategies as more younger, operable and fitter patients receive SABR.

Is the Importance of Heart Dose Overstated in the Treatment of Non-Small Cell Lung Cancer? A Systematic Review of the Literature

PURPOSE

Some recent studies have suggested a relationship between cardiac dose and mortality in non-small cell lung cancer (NSCLC), but others have reported conflicting data. The goal of this study was to conduct a systematic review and meta-analysis to provide an evidence-based estimate of the relationship between cardiac dose and mortality in these patients.

METHODS AND MATERIALS

A systematic review of MEDLINE (PubMed) and Embase databases (inception to January 2018) was performed according to PRISMA guidelines. Studies that evaluated cardiac dosimetric factors in patients with NSCLC and included outcomes of cardiac events, cardiac mortality, and/or overall survival were identified.

RESULTS

From 5614 patients across 22 studies, a total of 214 cardiac dosimetric parameters (94 unique) were assessed as possible predictors of cardiac toxicity or death. Assessed predictors included general (eg, mean heart dose [MHD]), threshold-based (eg, heart V5), and anatomic-based (eg, atria, ventricles) dosimetric factors. The most commonly analyzed parameters were MHD, heart V5, and V30. Most studies did not make corrections for multiplicity of testing. For overall survival, V5 was found to be significant on multivariable analysis (MVA) in 1 of 11 studies and V30 in 2 of 12 studies; MHD was not significant in any of 8 studies. For cardiac events, V5 was found to be significant on multivariable analysis in 1 of 2 studies, V30 in 1 of 3 studies, and MHD in 2 of 4 studies. A meta-analysis of the data could not be performed because most negative studies did not report effect estimates.

CONCLUSIONS

Consistent heart dose-volume parameters associated with overall survival of patients with NSCLC were not identified. Multiplicity of testing is a major issue and likely inflates the overall risk of type I errors in the literature. Future studies should specify predictors a priori, correct for multiplicity of testing, and report effect estimates for nonsignificant variables.

A systematic review and meta-analysis of stereotactic body radiation therapy versus surgery for patients with non-small cell lung cancer

OBJECTIVE

Stereotactic body radiation therapy is the preferred treatment modality for patients with inoperable early-stage non-small cell lung cancer. However, comparative outcomes between stereotactic body radiation therapy and surgery for high-risk patients remain controversial. The primary aim of the present meta-analysis was to assess overall survival in matched and unmatched patient cohorts undergoing stereotactic body radiation therapy or surgery. Secondary end points included cancer-specific survival, disease-free survival, disease recurrence, and perioperative outcomes.

METHODS

A systematic review of relevant studies was performed through online databases using predefined criteria. The most updated studies were selected for meta-analysis according to unmatched and matched patient cohorts.

RESULTS

Thirty-two studies were identified in the systematic review, and 23 were selected for quantitative analysis. Surgery was associated with superior overall survival in both unmatched (odds ratio, 2.49; 95% confidence interval, 2.10-2.94; P < .00001) and matched (odds ratio, 1.71; 95% confidence interval, 1.52-1.93; P < .00001) cohorts. Subgroup analysis demonstrated superior overall survival for lobectomy and sublobar resection compared with stereotactic body radiation therapy. In unmatched and matched cohorts, cancer-specific survival, disease-free survival, and freedom from locoregional recurrence were superior after surgery. However, stereotactic body radiation therapy was associated with fewer perioperative deaths.

CONCLUSIONS

The current evidence suggests surgery is superior to stereotactic body radiation therapy in terms of mid- and long-term clinical outcomes; stereotactic body radiation therapy is associated with lower perioperative mortality. However, the improved outcomes after surgery may be due at least in part to an imbalance of baseline characteristics. Future studies should aim to provide histopathologic confirmation of malignancy and compare stereotactic body radiation therapy with minimally invasive anatomical resections.

Video assisted thoracic surgery vs. thoracotomy for locally advanced lung squamous cell carcinoma after neoadjuvant chemotherapy

BACKGROUND

Surgery is an important part of multidisciplinary treatment strategy for locally advanced lung squamous cell carcinoma (LSCC), but insufficient evidence supports the feasibility and safety of video assisted thoracic surgery (VATS) following neoadjuvant chemotherapy for locally advanced LSCC. This study aims to compare perioperative data and long-term survival of locally advanced LSCC patients between VATS and thoracotomy after neoadjuvant chemotherapy.

METHODS

We retrospectively collected the clinical and pathological information of patients with locally advanced LSCC who underwent surgical resection after neoadjuvant chemotherapy from October 2013 to October 2017. All patients were divided into two groups (thoracotomy and VATS) and were compared the differences in perioperative, oncological and survival outcomes.

RESULTS

A total of 81 patients were analyzed in this study (67 thoracotomy and 14 VATS). VATS provided less postoperative pain (P = 0.005) and produced less volume of chest drainage (P = 0.019) than thoracotomy, but the number of resected lymph nodes was less in VATS group (P = 0.011). However, there was no significant difference in the number of resected lymph node stations and the rate of nodal upstaging between two groups. The mean disease free survival (DFS) was 32.7 ± 2.7 months for the thoracotomy group and 31.8 ± 3.0 months for the VATS group (P = 0.335); the corresponding overall survival (OS) was 41.7 ± 2.2 months and 36.4 ± 4.1 months (P = 0.925).

CONCLUSION

In selected patients with locally advanced LSCC, VATS played a positive role in postoperative recovery and associated similar survival outcome compared with thoracotomy after neoadjuvant chemotherapy.

Early stage lung cancer survival after wedge resection and stereotactic body radiation

BACKGROUND

The comparative effectiveness of stereotactic body radiation therapy (SBRT) and wedge resection in the treatment of early stage lung cancer is still under debate. This meta-analysis compares the 5-year overall survival (OS) of wedge resection and SBRT in patients with stage I non-small cell lung cancer (NSCLC).

METHODS

Original research articles published between 1995 and 2017 were identified through the National Library of Medicine and National Institutes of Health PubMed database and through the reference lists of reviewed articles. Data were processed and analyzed in R (version 3.4.2) and a summary estimate that accounted for the sample size of each study was calculated. The combined percent survival was calculated using random effect models. Funnel plots were used to assess publication bias. Heterogeneity was tested using the Q statistic and the I2 statistic.

RESULTS

There were 16 studies totaling 1,984 patients with stage I NSCLC treated with wedge resection. The meta-estimate was 74% (95% CI, 66-81%), with significant heterogeneity across studies (Q =172.46, P<0.0001; I2=91.30%). Thirty-six studies including 3,309 patients with stage I NSCLC treated with SBRT/SABR produced a meta-estimate of 44% (95% CI, 38-50%), with significant heterogeneity (Q =423.55, P<0.0001; I2=91.74%). Two articles directly comparing stage I NSCLC patients treated with wedge resection to patients treated with SBRT both reported higher 5-year OS after wedge resection.

CONCLUSIONS

SBRT is a treatment option reserved to medically inoperable patients, but could be an alternative to surgery in medically operable patients who prefer a less invasive treatment. More standardized methods for data collection and reporting are necessary to allow better comparisons across published studies.